Countercurrent gas and liquid contact installations generally comprise a chamber provided in its lower part with at least one gas inlet opening and in its upper part with at least one gas outlet opening and, inside said chamber, a liquid distributing system, a unit for putting the liquid in direct contact with the gas disposed under the distributing system, and means for receiving the liquid which flows in a free fall in the form of a shower or the like from the contacting unit. These means may be formed by a basin provided at the base of the chamber and into which the liquid falls directly. However, such a basin has the drawback of being of relatively expensive construction, of generating considerable noise due to the liquid falling through a considerable height from the contacting unit onto the liquid in the basin, and of requiring high pumping power for directly or indirectly recycling the liquid from the basin to the distributing system. In an attempt to overcome these drawbacks, it is already known, in particular from French Patent No. 876,525, to employ liquid receiving devices which are disposed immediately below the exchange unit and each comprise a liquid receiving wall which is inclined to the vertical and pours the liquid received into a trough which extends along the lower edge of the wall. A number of these devices are disposed parallel to each other and overlap, so as to prevent any direct fall of the liquid from the exchange unit to the base of the tower, and pour the collected liquid at one of their ends into a trough then into a final collector.
However, with the receiving devices of the prior art, there is observed poor flow of the collected liquid in the troughs. This has usually resulted in the provision of secondary collectors for avoiding, to some extent, clogging of the troughs.